Easy-open structure for containers



June 17, 1969 w. T. SAUNDERS "3,450,300

EA$YOPEN STRUCTURE FOR CONTAINERS Filed Jan. 22, 1968 Sheet of 4 f 1' H11 FIG? WILLIAM T. SAUNDERS BY -sw ATTORNEYS INVENTOR June 17, 1969 w. T. SAUNDERS EASY-OPEN STRUCTURE FOR CONTAINERS Sheet Filed Jan. 22, 1968 FIG, 3

FIG. 4

INVENTO R WILLIAM T. SAUNDERS FIG. 5

. ATTORNEYS June 17, 1969 w. T. SAUNDERS EASY-OPEN STRUCTURE FOR CONTAINERS J-or4 Sheet Filed Jan. 22, 1968 FIG. 9

FIG. 8

He. II

INVENTOR WILLIAM T. SAUNDERS ATTORNEYS June 17, 1969 w. r. SAUNDERS 3,450,300

EASYOPEN STRUCTURE FOR CONTAINERS Filed Jan. 22, 1968 Sheet 4 of 4 INVENTOR WILLIAM T. SAUNDERS ATTORNEYS United States Patent EASY-OPEN STRUCTURE FOR CONTAINERS William T. Saunders, Weirton, W. Va., assignor to National Steel Corporation, a corporation of Delaware Filed Jan. 22, 1968, Ser. No. 699,732 Int. Cl. B65d 17/24 US. Cl. 22054 28 Claims ABSTRACT OF THE DISCLOSURE Class 1 and Class 2 lever action are combined in a novel easy-open structure for containers. The combined lever action causes rupture of a container wall along preformed scorelines in two locations on opposite sides of securing means for an integral opener. An arch-shaped tear segment results from movement of the handle end of the integral opener in a direction away from the container. Further removal of the container wall is determined by scoreline configuration. For removal of a wall or a major portion of a wall of a container, a tear segment is formed around a substantial portion of the wall prior to total removal. In a pour feature embodiment, the length of the tear segment can be limited dependent on the size of the opening. The invention provides easyopen features for full-open containers, and the like, without inhibiting use of profiling as required for strengthening walls of pressure pack containers.

This invention is concerned with novel easy-open structure for containers.

Most prior easy-open containers rely on a rigid-arm, integral opener and the mechanical advantage developed by such rigid-arm opener when rupturing a scored portion of a wall of the container. Where a Class 1 lever action has been employed in the prior art, a part of the force applied to open the container is lost in establishing a fulcrum point for the opener, e.g., about a rivet or other means used for securing the opener to the container. Where Class 2 lever act-ion has been employed initial rupture has been dependent on breakage of the container wall under tension. These disadvantages become pronounced when working with sheet metal containers. For dispensing contents of soup cans, meat containers, and the like, it is desirable that substantially the entire end wall be removed. Providing a hand-openable container which is strong, yet easily openable, is particularly diflicult with such full-open containers. In addition, such endwalls often require profiling, such as reinforcing ribs, to prevent endwall bucking. As a result, such endwalls are diflicult to bend during opening.

Numerous :prior art proposals for overcoming this problem have been made. It has been proposed to provide a tear strip which spirals from a centrally located puncture region around the periphery of the endwall. This arrangement is disadvantageous because a relatively narrow-width tear strip tends to break, leaving sharp edges which may be gripped in order to complete pullout of the endwall.

Also, it has not been possible to remove an entire endwall based on principles used in providing pour openings since bending or folding of the pull-out portion and tearing along closely spaced score 'lines is relied upon in making such openings. Such aids to easy opening are not available when making a full opening, especially where strengthening ribs are employed.

The present invention provides a unique combination of Class 1 and Class 2 lever action, eliminates a spiral tear strip in making a full-open container, and permits use of container walls made from high strength material, such as sheet metal, with or without the reinforcing profiling required for withstanding the high pressures often encountered in packing, processing, or handling. These advantages of the invention provide for easy opening of pour feature as well as full-open containers.

Other objects and advantages of the invention are inherent in the following description of several embodiments of the invention shown in the accompanying drawings.

In these drawings:

FIGURE 1 is a plan view of a full-opening container embodying the principles of the invention;

FIGURE 2 is an enlarged cross-sectional view on line 2-2 of FIGURE 1;

FIGURE 3 is an enlarged view on section line 3-3 of FIGURE 1;

FIGURE 4 depicts the structure of FIGURE 3 in an initial phase of a container-opening operation;

FIGURE 5 illustrates the structure of FIGURE 4 in a later phase of the opening operation;

FIGURE 6 is an isometric view of a portion of the container of FIGURE 1 in a later phase of the opening operation than that shown in FIGURE 5;

FIGURE 7 is a side elevational view of the container of FIGURE 1 showing a final stage in the opening opcation;

FIGURE 8 is a plan view of a pour-opening container embodying the principles of the invention;

FIGURE 9 is an enlarged detail view of a portion of the container of FIGURE 8;

FIGURE 10 is an isometric view of a sidewall-opening container embodying the principles of the invention;

FIGURE 11 is a plan view of another fullopening container embodying the principles of the invention; and

FIGURE 12 is a plan view of still another full-opening container embodying the principles of the invention.

In FIGURE 1, a tlnplated steel container generally indicated at 12 has a top end wall or lid 14. Lid 14 is secured by a conventional chime seam 15 to a hollow, cylinderical can body 16 (FIGURES 6, 7) having continuous side walls. A bottom end wall (not shown) can be integral with the sidewall or secured to body 16 by another conventional chime seam 17. A continuous outer scoreline 18 is diminished metal thickness (FIGURES 1, 2) is formed in the outside of lid 14. Scoreline 18 circumscribes lid 14, defining a removable portion 20 of lid 14. Removable portion 20 includes substantially the entire area of lid 14. Removable portion or pull-out 20 is generally circular in shape.

An inner scoreline 22 is formed in pullout 20. This scoreline is radially inwardly of scoreline 18. Inner scoreline 22 is equally spaced from outer scoreline 18 along a portion of its length and extends a distance of about around the periphery of pull-out 20. Scorelines 18 and 22 coact to define an arch-shaped tear segment or strip 24 which is narrower in width relative to pull-out 20. Tear strip 24 is of relatively uniform width along a major portion of its length in approaching its opposite ends 26, 28 located at the opposite ends of scoreline 22. Tear strip 24 also includes a mid-section of non-uniform width generally indicated at 30.

A circular reinforcing rib 34 and depressed central panel 36 are formed in pull-out 20 (see also FIGURE 3). Such profiling strengthens the lid and helps prevent endwall buckling during packing and processing. Tear strip 24 has the cross-sectional configuration of a reinforcing rib or bead (FIGURE 2). This rib is formed by flow of metal from the scored regions of pull-out 20, during the scoring operation. A scoreline 32 of diminished metal thickness can be formed to connect the ends of scoreline 22. Scoreline 32 is substantially equally spaced from outer scoreline 18 around the remaining 180 of the periphery of pull-out 20. For example, the residue metal thickness of scoreline 32 can be about twice as thick as the metal of scoreline 22. Provision of scoreline 32 around pullout 20 forms a rib around the remainder of the periphery of pull-out 20 and provides a uniform appearance. Scoreline 32 can be eliminated entirely or made the same depth as scoreline 22 without substantially altering the opening features provided.

A tab opener 38 is secured to tear strip 24 in midsection of the tear strip by a rivet which is formed in a conventional manner from metal of lid 14. Rivet 40 includes a head 42 (FIGURE 3) and a shank 44. Opener 38 includes an aperture for receiving the rivet shank and a depressed portion 52 for receiving rivet head 42. Opener 38 is elongated and rigid, and is formed of sheet metal having peripheral downturned edges. The opener has a ring-pull handle portion 46 extending away from rivet 40 in a direction toward the central portion of lid 14. A puncturing end portion 48 of opener 38 extends away from rivet 40 in a direction opposite to that of handle 46. With opposite end portions 46, 48 unattached, opener 38 can act as a lever having a fulcrum in the region of rivet 40. Gripping of handle end 46 is facilitated by recessed panel 36, so that a separate finger depression in lid 14 for this purpose is not required.

Inner scoreline 22 and outer scoreline 18 have starter sections generally indicated at 54 and 56, respectively. Starter sections 54, 56 are adjacent rivet 40 on opposite sides of the rivet and define the tear segment at midsection 30 of the tear strip 24.

Although rivet 40 holds opener 38 to lid 14, it is possible that the opener could become misaligned relative to the starter sections by rotational movement about the rivet in a direction generally parallel to the plane of the lid. To restrain such movement, a pair of raised protrusions 57 (FIGURE 1) are formed in lid 14 closely adjacent opposite sides of opener 38. Protrusions 57 constrain rotational movement of opener 38.

Starter section 54 of inner scoreline 22 underlies opener 38 and includes a point-like configuration 58 projecting away from rivet 40. Pointed portion 58 is slightly rounded, providing the adjoining section of tear strip 24 with a nipple-like configuration.

Starter section 56 of outer scoreline 18 is contiguous puncturing end 48 of opener 38. Puncturing end 48 is aligned with starter section 56 to exert a localized pressure on the tear strip closely adjacent the starter section upon movement of end 48 in a direction toward lid 14.

Starter section 54 of inner scoreline 22 is in a position to be ruptured with movement of handle 46 in the direction of arrow 60 (FIGURE 3) away from lid 14. This provides one of the important advantages of the invention. Upward force on handle 46 is transmitted by way of rivet head 42 and shank 44 to rupture starter section 54 by Class 2 lever action (FIGURE 4) and the force ordinarily lost in establishing a fulcrum point for an opener is utilized for opening the container. Pointed portion 58 of scoreline 22 facilitates initial rupture by concentrating stresses in the region of the point.

Movement of handle 46 away from lid 14 also moves puncturing end 48 of the opener in a direction toward the lid, so that end 48 applies localized pressure on tear strip 24 at starter section 56 of outer scoreline 18. Thus, with movement of handle 46, opener 38 also acts as a Class 1 lever and puncturing end 48 ruptures starter section 56 of outer scoreline 18 (FIGURE 5 Placement of outer scoreline 18 closely adjacent chime seam 15 not only maximizes the size of the pull-out, but also permits the perimeter of the container to provide backing for initial scoreline rupture.

It is preferred that outer scoreline 18 be formed in the exterior surface of lid 14 in order to facilitate puncture of starter section 56. With such arrangement, there is less opportunity for diffusion of the force applied by 4 puncturing end 48. Although external scoring is thus preferred, internal scoring can be used.

In practice, although starter section 54 of inner scoreline 22 is generally ruptured prior to rupture of starter section 56 of outer scoreline 18, the starter sections are ruptured in rapid sequence. The starter section of inner scoreline 22 is preferably ruptured first to provide a vent opening for equalization of pressure inside and outside a container. In such cases, opener 38 acts as a battle to prevent scattering of container contents through the vent opening during such equalization.

After the starter sections of both scorelines have been ruptured by the double lever action of opener 38, the opener is pulled upwardly and ba-ckwardly ac-ross lid 14 in the direction of arrow 61 (FIGURE 6). This action tears each scoreline 18, 22 in opposite directions from rivet 40. The directions of tearing initially diverge from one another, and gradually approach parallelism at the ends of the tear strip. The tear strip bends as the opener is pulled away from lid 14 which facilitates opening by favorably orienting tearing force components.

Except for tear strip 24, pull-out 20 remains flat so that only metal in the relatively narrow tear strip is bent during this phase of the opening of the container. At the ends of the tear strip, tearing along inner scoreline 22 terminates. However, tearing continues along outer scoreline 18, in directions converging on a point opposite rivet 40. As tearing proceeds, pull-out 20 is lifted from the container (FIGURE 7), but still remains essentially fiat, except for the tear strip. Tearing along the full length of outer scoreline 18 completely severs pull-out 20 from lid 14.

Tear strip 24 should be as narrow as practicable to facilitate opening by minimizing the amount of metal that is bent during the opening operation. The width of the tear strip will vary in accordance with the size of the container, and the strength of the material of the wall. For example, in a full-opening tinplated steel container having a diameter of about 2.6 inches, the tear strip can be about 0.125 inch wide. This dimension is a straightline distance between scorelines, and is generally uniform except in the region of the rivet. At the rivet location, the distance between the pointed portion of the starter section of the inner scoreline and the starter section of the outer scoreline is about 0.279 inch. The centerline of the rivet is about 0.131 inch away from the pointed portion of the inner scoreline. The distance from the rivet centerline to the outer scoreline is about 0.148 inch. The starter section of the inner scoreline should generally be about 0.1 inch in all directions from the rivet centerline with a steel lid of about 0.008 inch in thickness, to avoid possible breakage of the tear strip during manipulations of opener 38. The rivet has a shank diameter of about 0.075 inch, prior to head forming. The cross-sectional configuration of the tear strip is relatively fiat in the region of the rivet, because of restraining action of the rivet on score metal flow and because of the rivet headforming operation required to attach tab opener 38.

The tear st-rip preferably extends about around the periphery of the removable portion of a container. However, the tear strip, the length of which is determined by the length of the inner scoreline, can terminate short of 180, or can extend beyond 180 to 270 01' more. If inner scoreline 22 extends substantially the full 360 about the lid, removable portion 20 will still pull out with the tear strip as the tearing of outer scoreline 18 is completed in preference to the inner scoreline at this point. A tear strip extending a distance of about 180 in a circular lid has been found to be adequate. In a rectangular lid, a tear strip extending about half the distance around the periphery of the lid is sufficient.

In manufacturing a lid 14, a circular blank is provided with a desired profile formed in the conventional manner. Rivet formation is then initiated by deformation of a portion of the lid in suitable dies to produce a protrusion at the rivet location. The size of the protrusion is then reduced in a sequence of progressively smaller dies. This technique permits formation of small rivets without tearing the lid metal. After rivet formation, scorelines are made and a pull tab placed over the rivet. A rivet head is then formed, to secure the tab to the lid. The requence of the foregoing profiling and rivet formation steps can be altered if desired. With a steel lid of 0.008 inch in thickness, scorelines 18 and 22 can have a residue metal thickness of about 0.0015 inch or residue metal can be increased to about .003" or decreased to about .0005" dependent on the requirement of the particular pack.

FIGURES 8 and 9 illustrate a container intended for pourable material. The container is generally indicated at 62 and includes an end wall 64 in which a raised reinforcing rib 66 is formed. A continuous outer scoreline 68 formed in end wall 64 defines a removable pourfeature pull-out 70 constituting a minor portion of the wall area. An inner scoreline 72 is formed in pull-out 70 and coacts with scoreline 68 to define an arch-shaped tear segment or strip 74. Inner scoreline 72 has a starter section which is generally indicated at 76 and includes a pointed portion 78. Outer scoreline 68 includes a starter section generally indicated at 80. The starter sections are on opposite sides of a rivet 82 which secures a tab opener 84 (FIGURE 9) to end wall 64. FIGURE 8 does not show opener 84 or a head on rivet 82 for purposes of clarity.

With movement of handle portion 86 of opener 84 in a direction away from end wall 64, opener 84 ruptures starter sections 76 and 80 in rapid sequence by Class 2 and Class 1 lever action in the manner discussed above in relation to FIGURES 3, 4, and 5. By .pulling opener 84 away from end wall 64 after initial rupturing, tearing proceeds along scoreline 68 to the end of pull-out 70. When tearing is completed, pull-out 70 is completely detached. The container contents can be dispensed through a pour opening left by removal of pull-out 70.

A generally U-shaped, raised guide rib 88 restrains rotational movement of opener 84 about rivet 82 in a direction generally parallel to wall 64, thus preventing accidental misorientation of opener 84 relative to the starter sections of the scorelines. Rib 88 also strengthens the container walls to prevent buckling, provides backing for the initial ruptures, and protects the lips of a person drinking from the container from raw edges of the pour opening. A recessed panel 71 in pull-out 70 strengthens removable portion 70 and facilitates gripping opener 84.

Opener 84 is generally wedge-shaped, with opposite sides diverging in a direction away from rivet 82. The sides of opener 84 cross outer scoreline 68 at locations near the rivet. This arrangement is advantageous in several respects. One of these is a slight spreading by the sides of the opener of the opening made by rupture of the scoreline 68, when the puncturing end of opener 84 and adjacent tear strip metal project a short distance into the container. Spreading of the opening prevents binding of the tear strip metal on the periphery of the opening when the tear strip is withdrawn through the opening in a later phase of the container opening operation. Applicants copending application Ser. No. 599,442., filed Dec. 6, 1966, contains a complete discussion of the advantages of such structure and is incorporated herein by reference.

FIGURE illustrates a side-wall opening container generally indicated at 90. An outer scoreline 92 defines a pull-out or removable portion 94 of side walls 96 of container 90. An inner scoreline 98 extends around a segment of the periphery of pull-out 94, and coacts with outer scoreline 92 to define an arch-shaped tear segment or strip 100. A generally T-shaped tab opener 102 is secured by a rivet 104 to tear strip 100 in the mid-section of the tear strip. Movement of handle portion 106 of opener 102 in a direction away from side Walls 96 causes the opener to rupture starter sections of scorelines 92, 98

in the fashion discussed above. Pulling opener 102 away from side wall 96 tears along the scorelines as tear strip bends away from the sidewalls. When the ends f inner scoreline 98 have been reached by the tearing action, tearing continues only along outer scoreline 92, and removable portion 94 is pulled away from sidewalls 96. Tear-ing continues along continuous scoreline 92, until pull-out 94 is completely severed from sidewalls 96.

FIGURE 11 illustrates a non-circular, full-opening container constructed in accordance with the invention. A container generally indicated at 108 includes an end Wall or lid 110 of rectangular shape. A continuous outer scoreline 112 defines a pull-out 114 in lid 110. An inner scoreline 116 coacts with outer scoreline 112 to define an archshaped tear segment or strip 118 which extends between the scorelines around a peripheral segment of pull-out 114. An opener 120 is secured to tear strip 118 by a rivet 122, in the midsection of the tear strip. Lifting handle portion 124 of opener 120 away from lid 110 ruptures starter sections of the scorelines by Class 1 and 2 lever action, in the manner discussed above. With the tear strip started, opener 120 is pulled away from lid 110, tearing along the scorelines in opposite directions on both sides or rivet 122 until the ends of inner scorelines 116 are reached. Thereafter, tearing continues only along outer scoreline 112 and pull-out 114 is lifted away from lid 110. When the metal of outer scoreline 112 is severed all around pull-out 114, the pull-out is detached from container 108.

FIGURE 12 depicts a full-opening container of the type particularly useful for packing hams. This container is generally indicated at 126 and includes a lid 128. A continuous outer scoreline 130 defines a generally ovalshaped pull-out 132 in lid 128. An inner scoreline 134 coacts with outer scoreline 130 to define an arch-shaped tear segment or strip 136. Tear strip 136 extends between the scorelines around a peripheral segment of pullout 132. A third scoreline 138 of increased residue metal thickness relative to scoreline 134 extends between the ends of scoreline 134 around the remainder of the periphery of pull-out 132.

An opener 140 is secured to the midsection of tear strip 136 by a rivet 142. Lifting handle portion 144 of opener 140 away from lid 128 ruptures starter sections of scorelines 134, 130 by Class 2 and Class 1 lever action in the fashion hereinbefore discussed. After the tear strip is started, opener 140 is pulled upwardly and backwardly across lid 128. This action causes tearing along scorelines 130, 134, to the ends of inner scoreline 134. Thereafter, as handle 140 is pulled upwardly and backwardly, tearing continues only along outer scoreline 130 and pullout 132 is lifted from the plane of the line. At completion of tearing of the metal of scoreline 130 all around pullout 132, the pull-out is completely severed from container 126.

Hand-openable containers according to the invention are highly advantageous. The containers can be constructed with walls which are made from relatively strong materials, including steel, and which include extensive reinforcing profiling required to withstand high pressures encountered in many packing and processing operations. Use of spiral tear strips of the prior art has been avoided by a structure which makes opening easier and safer than use of spiral tear strips. Also, full-opening containers with stronger walls can be readily accommodated.

Containers according to the invention are easier to open because all the force of initial rupture is utilized by arrangement of the tab opener to act as both a Class 1 and Class 2 lever. With this structure, tension established in the container wall between the rivet and the end of the opener handle is employed to high advantage in rupturing a scoreline by Class 2 lever action, yet the advantages of a Class 1 lever are not lost.

The inventive structure, in making possible the use of steel and other relatively strong materials for container walls, is also advantageous because it permits the use of small rivets to attach the tab opener to the container. Small rivets cannot be used with weak materials, and are desirable because relatively little material from the container wall is required for rivet formation. This in turn permits the rivet to be located close to the perimeter of the wall. Formation of large rivets can weaken a container wall when the metal is stretched to form the rivet. This is particularly disadvantageous when the weakened area is located close to the perimeter of a container wall because buckling of the wall tends to occur under such conditions. Further, placement of the rivet close to the edge permits use of a larger handle for maximum mechanical advantage.

Although the invention is employed to best advantage in containers made from steel, other materials including plastic, aluminum and other metals, and metal foil-paper laminates, can be employed. And while particular advantage is obtained by securing the tab opener to the container wall by a rivet, other securing arrangements, including welding, can be used.

The invention has been described in connection with several illustrated embodiments, but modification of those embodiments can be made without departing from the principles of the invention. Such modifications are within the scope of the invention as defined by the appended claims.

What is claimed is:

1. Container easy-open structure comprising a container wall,

an outer scoreline of diminished material thickness located on the container wall defining a removable portion of such wall,

an inner scoreline of diminished material thickness located within the removable portion of the container wall,

the scorelines defining a tear segment in the container wall located between the scorelines,

an opening member, and

securing means for securing the opening member to the tear segment,

the opening member including a handle end in spaced relationship from the securing means,

the inner scoreline having a starter section at the tear segment adjacent the securing means at a position to be ruptured with movement of the handle end of the opening member in a direction away from the container wall,

the outer scoreline having a starter section at the tear segment adjacent the securing means at a position to be ruptured with movement of the handle end of the opening member in a direction away from the container wall,

the rupture of one of the starter sections being by Class 1 lever action and the rupture of the other stater section being by Class 2 lever action,

the starter sections of the scorelines being located on opposite sides of the securing means so that the securing means is completely within the tear segment.

2. The structure of claim 1 in which the opening member includes an end portion adjacent the securing means,

the end portion of the opening member adjacent the securing means including means for rupturing the starter section of the outer scoreline by Class 1 lever action.

3. The structure of claim 2 in which the starter section of the inner scoreline includes a pointed configuration with the starter section of the inner scoreline being ruptured by Class 2 lever action.

4. The structure of claim 1 in which the tear segment extends between the scorelines around a peripheral segment of the removable portion of the wall.

5. The structure of claim 1 in which the' starter section of the inner scoreline adjacent the securing means includes a pointed configuration.

6. The structure of claim 5 in which the pointed configuration of the inner scoreline starter section projects in a direction away from the securing means.

7. The structure of claim 1 in which the tear segment has opposite ends and a midsection, and the opening member is secured to the midsection of the tear strip.

8. Container easy-open structure comprising a container wall,

an outer scoreline of diminished material thickness defining a removable portion of the container wall,

an inner scoreline of diminished material thickness located within the removable portion of the container wall,

the scorelines defining a tear segment extending between the scorelines around a peripheral segment of the removable portion of the wall,

an opening member, and

securing means for securing the opening member to the tear segment,

the opening member having a handle end and a remaining end located on opposite sides of the securing means,

the inner scoreline having a starter section located in close proximity to the securing means at a position to be ruptured by Class 2 lever action with movement of the handle end of the opening member in a direction away from the wall,

the outer scoreline having a starter section,

the starter sections of the inner and outer scorelines being located on opposite sides of the securing means,

the remaining end of the opening member including rupturing means for rupturing by Class 1 lever action the starter section of the outer scoreline with movement of the handle end of the opening member in a direction away from the wall.

9. The structure of claim 8 in which the tear segment has opposite ends and a midsection and the opening member is secured to the midsection of the tear segment.

10. The structure of claim 9 in which the tear segment has an arch-shaped configuration having a generally uniform width between the midsection and its opposite ends with the width being narrow relative to dimensions of the removable portion of the wall,

the arch-shaped tear segment being separated from the container wall by pulling the opening member in a direction across the container wall after rupture of the starter sections, and separation of the removable portion being completed by further pulling of the opening member.

11. The structure of claim 8 in which the tear segment extends about around the periphery of the removable portion of the wall.

12. The structure of claim 8 in which the removable portion of the wall includes profiling means for increasing the strength of the removable portion.

13. The structure of claim 12 in which the tear segment includes profiling rib means reinforcing the tear segment, the rib means being formed by scoremetal flow.

14. The structure of claim 13 in which the inner scoreline is generally parallel to the outer scoreline and has opposite ends,

the removeable portion of the wall includes a second inner scoreline of diminished material thickness extending generally parallel to the outer scoreline between the ends of the first-named inner scoreline, and

the second inner scoreline is of increased material thickness relative to the first-named inner scoreline.

15. The structure of claim 8 in which the rupturing means at the remaining end of the opening member is aligned with and contiguous the starter section of the outer scoreline.

16. The structure of claim 15 in which the scorelines are formed on an exterior surface of the container wall,

17. The structure of claim 8 in which at least a major portion of the starter section of the inner scoreline underlies the opening member, with the starter section of the inner scoreline being positioned to be ruptured upon movement of the handle end of the opening member away from the container wall and the starter section of the outer scoreline being positioned to be ruptured subsequent to rupture of the inner scoreline.

18. The structure of claim 17 in which the starter sections of the scorelines are positioned to be ruptured in rapid sequence.

19. The structure of claim 17 in which the starter section of the inner scoreline includes a pointed configuration underlying the opening member and projecting in a direction away from the securing means.

20. The structure of claim 8 in which the removable portion of the container wall constitutes a major portion of a wall of the container.

21. The structure of claim 20 in which the container wall is an end wall,

22. The structure of claim 8 in which the removable portion of the wall constitutes a minor portion of an endwall of the container defining a pour opening.

23. The structure of claim 8 including restraining means for restraining rotational movement movement of the opening member about the securing means in a direction generally parallel to the container wall.

24. The structure of claim 23 in which the restraining means comprises raised guide means formed in the wall adjacent to the opening member.

25. The structure of claim 8 in which movement of the rupturing means is in a direction toward the container wall with movement of the handle end of the opening member in a direction away from the wall.

26. The structure of claim 8 in which the securing means comprises a unitary rivet, the rivet being formed from material of the container wall.

27. The structure of claim 8 in which the container wall comprises sheet metal.

28. The structure of claim 27 in which the sheet metal comprises steel having a protective coating.

References Cited UNITED STATES PATENTS 3,283,946 11/1966 Stec 220-44 XR 3,381,848 5/1968 Brown 220-54 GEORGE T. HALL, Primary Examiner. 

